Under My Skin
by Dr. Sexy M.D
Summary: Bodyswap! Castiel decides that Sam and Dean need to stop fighting and switches their bodies. Originally intended to be a multi-chapter, but I added it to my one-shot list. :) *This is full of fun, steam and sweetness!


AN: I would've had this story done a couple days ago, but it took me forever to find the right title for it. I usually try to use a classic rock song as the title, but I had a hard time finding just the right thing until I stumbled upon this Aerosmith song. :)

I hope this isn't too confusing. It's a body swap, but I tried to make it obvious who was inside what body and who's actually body they were using. It's hard to explain, but I hope it makes sense. This is something I've wanted to do for a LONG time. I had the first 700 words already written from a long time ago. :)

For anyone who's interested and doesn't already know, Double Trouble (Double Vision's sequel) is on sinful-desire dot org. I have the first 13 chapters posted and try to update almost every day. :)

* * *

Under My Skin

"Bitch!" Dean exclaimed, plopping down onto his bed, shooting a glare at his annoying little brother.

Sam rolled his eyes, "jerk!"

If they were being honest, neither of them really knew what they were arguing about this time. It seemed as though there was always something to bicker about; the hunt they were on, who was going to drive the car, what music they would listen to and what motel they would stay at. It didn't really matter what they were arguing about, they just loved to argue.

Unfortunately when you spent every hour of every day with someone they tended to get on your last nerve. No matter where they went the other was always there; there was no frigging privacy from each other.

Sam dropped down into the desk chair and affixed himself in front of his computer. At least he could surf the internet as a means to get some peace from his extremely obnoxious brother. He flipped it open and groaned when he discovered that once again his asshole of a brother had fucked with his computer. "What the hell, man? How many times have I told you not to mess with my stuff?"

"Shut up, I didn't do anything." Dean whined defensively.

Sam rolled his eyes, "Well, for some reason it's frozen on another porn site." Something on the screen caught Sam's eye and he turned back to stare for a moment, "Cougars Dean, really?"

Dean shrugged, "What? Come on Sam, you gotta lighten up!"

Sam sighed, "And you gotta stop touching my stuff!"

"You wouldn't have even known if your computer wasn't such a flaming pile of elephant crap!" Dean rolled his eyes. So what if he used Sam's computer to find some porn, so what? It's not like there was really that much to do around that craphole town.

"So, this is somehow my fault?" Sam asked, wanting to reach over and punch Dean in the head.

"Shut up, Sam!"

"No, for once you're gonna shut up, Dean!"

Dean raised his eyebrow, "Or what? What are you going to do, Sammy huh, cry?"

"I'm going to fucking punch you in the face, that's what I'm going to do. Now, leave me and my stuff the hell alone!"

Dean flinched as if he had actually hit him. He rarely ever saw Sam act like that. He sighed, "I'm sorry, I shouldn't have just said that. I was trying to lighten the mood."

Sam relaxed his shoulders a bit, "Maybe I overreacted a little bit too, it's just that-"

Before Sam could finish his sentence Castiel was standing in the room, at the foot of Dean's bed. "You two must stop the fighting at once!"

Dean raised his eyebrow at his usually friendly angel, "We were just apologizing, Cass. Don't get your panties in a bunch."

Sam smiled, "Besides, we are brothers, arguing is normal."

Castiel frowned dramatically, "The two of you being at odds with each other tips the world onto its side. I'm glad to hear that you have made up."

"Yeah, and if Dean can just stay away from my stuff then we will continue to be fine." Sam added.

Dean frowned, "It would be nice if he could stop acting like a bitch all the damn time too."

Sam glared at Dean again the way he had been minutes before, "I'm not the one being a bitch here, Dean!"

Castiel raised his hands and sighed, "Very well. If you two refuse to settle this yourselves then I will be forced to step in." With that he touched each brother's forehead and then vanished, without another word.

Sam and Dean looked at each other. Dean's eyes were wide, "What the hell was that all about?"

Sam shook his head, "I have no fucking clue."

"Did he seem a little extra constipated to you?" Dean asked.

Sam smiled, "Uh…yeah, a bit." That was an understatement.

Dean shrugged, "I wonder if angels get PMS."

* * *

The next morning, when they woke up, things were quite freaky.

Sam woke first, like he usually did. He tossed the covers off his body and padded his way to the bathroom to pee. The peeing would alleviate the boner that he didn't even need to look down to see. That was pretty standard. They both woke up that way and tried to pretend that it wasn't happening.

Anyway, Sam took his piss, his eyes pretty much just slits. Then he turned on the shower to wash up. He stepped in and started to lather up his body. He kept his eyes shut and let the water rush over his naked body. He was so blasted sore…sorer than usual it seemed. He just chalked it up to the hunt. He was getting older everyday too.

He reached for his shampoo and poured a quarter sized amount in his hand. He brought the shampoo up to his head and nearly screamed. What the fuck?! His hair was short! Shit. He sent mental death rays to his sleeping brother. The asshole must've cut his hair in the night, thinking he was being cute. Well, it wasn't fucking cute. He liked his hair the way it was, dammit.

He was about to throw a bitch fit, but figured that's what Dean wanted him to do. So, he just closed his eyes and took a deep breath in through his nose. 'Don't freak out, don't freak out.' He instructed himself.

He opened his eyes and reached for his towel. He used it to dry off and then wrapped it around his waist. Then he had to do the thing he was dreading the most…he had to look at himself in the mirror. He needed to see how badly Dean had butchered his hair. He was sure he'd need a barber first thing.

When he stepped in front of the mirror and opened his eyes he actually did let out a blood curdling scream.

The scream woke Dean. He went running into the bathroom. "Sammy, what's—holy fucking shit on a shingle! What the hell is going on here?"

Dean's mouth was hanging open as he gazed on Sam's body. Or maybe he should say…his body. Because his younger brother was wearing his fucking meat suit! How the hell was that possible? What, did they now look like twins? Why and how did this happen?

When Sam looked over at him he went completely pale…paler than he'd already been…and dropped to the floor. He was completely out.

* * *

"Sam! Sammy, come on! Wake the fuck up!" It hadn't taken Dean all that long to figure out why Sam had passed out. The voice alone was a giveaway. They had clearly somehow switched bodies. He kicked Sam lightly in the side, "Would you open my damn eyes please? Quit being such a drama queen!"

Sam blinked and sat up, rubbing his head. He looked up at Dean and panic started to set in again.

Dean put one of Sam's gigantic hands up and said, "Don't pass out again, okay? We'll figure this shit out."

"How?"

"I don't know. We'll call Bobby or something. Maybe he'll know what to do."

Sam shook his head, "How did it happen?"

Dean shrugged, "I don't know. I know it wasn't the hunt because shape shifters don't have power like that."

Sam drew in his breath, figuring out what it must've been. "Remember pissy Cass coming in here last night?"

Dean groaned, "Yeah, that bastard must've done something to us." He looked up at the ceiling, "Not fucking funny, Cass!"

Sam sighed and got to his feet. He realized that his towel had come free when he dropped to the ground and he frantically tried to cover himself up.

Dean smiled, "You don't need to hide my body from me. I'm very familiar with it. You, however, are not allowed to look at me…er you…or whatever. Just don't look in a fucking mirror! Don't look down either." Sure, there'd been some weird flirting between them over the last few months, mostly when they'd been drunk, but it hadn't ever gone past that.

Sam flashed Dean the bitch face. "The same goes for you, asshole!"

Dean smirked, "Don't worry; I don't want to see any of it."

Sam rolled his eyes, "Yeah right. You know you want me. You at least can't wait to sneak a fucking peek."

Dean glared at his brother, "Keep dreaming, Sam!"

Sam folded his arms over his chest, "Uh huh…why don't you keep telling yourself that, Dean?" He followed Dean out into the main room. "You know you're wondering about how we measure up at least."

Dean grumbled. "You're a fucking giant, Sam…you do the math!"

Sam smiled, "I bet you're no slouch, Dean. You are my brother."

Dean's eyes widened, "This conversation is just so fucking wrong!"

Sam laughed, "Oh come on."

"What happened to the Sam who just passed out on the bathroom floor from pure terror?"

"I wasn't terrorized. I was shocked. I didn't think this was possible…but now that I know what happened, I'm okay."

"Who cares what happened. We should be focusing on how to fix it." Dean plopped Sam's giant body down on the end of his bed. "Shit, how do you move around in this thing?"

Sam smiled, "You'll get used to my meat…"

Dean gulped. Then he narrowed his eyes at Sam, "If you didn't look so damn sexy right now I'd punch you in the face!"

Sam burst into laughter. "Maybe you should punch yourself in the face."

Dean rolled his eyes, "I'm mad, not crazy!"

* * *

Dean took a shower too. He didn't even look down at Sam's shlong once…okay, maybe he did once, but it was all an innocent accident. He bit back his gasp. Shit, his brother was hung like a fucking horse.

Suddenly his head snapped back up and he refused to look at it anymore. Shit. There was something really wrong with this whole thing. He was getting turned on…getting a boner…from looking at Sam's dick…the one he was currently wearing. This was just fucking weird and wrong on so many damn levels.

'You will not get hard, you will not get hard.' Dean chanted over and over again. He was angry at that monster cock and wanted it to go back down.

Unfortunately, Sam's dick had other plans. It refused to submit to Dean's will. Dean groaned in annoyance. He slapped it, "Go away! Why won't you go away?!"

Sam knocked on the door, "Everything okay in there?"

"Yeah." Dean squeaked. "Just peachy!"

He could hear Sam laughing as he walked away from the bathroom door.

Dean nearly slammed his head against the shower, his eyes slipping shut. He didn't understand what the hell was going on. Why was he so damn horny? Was this what Sam went through every day? He found that impossible to believe. "Okay, fuck you." He yelled in the vicinity of that monster cock, "I'm just going to ignore you."

He quickly finished his shower and dried off. He was still half hard when he walked out of the bathroom, desperately trying to hide it from Sam.

Sam's whole face lit right up and his eyes went there. "What's going on, Dean?" He asked with amusement.

Dean sighed, "It won't go away." He shook his head, "How do you deal with this thing all the time? Got a mind of its fucking own."

"I bet it had nothing to do with the person wearing it, either. I bet you weren't looking at it and getting horny…"

"Shut up! I'm having a real problem here." Dean nearly whined.

Sam laughed. He walked to Dean then dropped down onto his knees. "Guess I'll just have to take care of it."

He got even fucking harder…but Dean refused to comply. He backed up and exclaimed, in an outraged voice, "No! Go away, Sam!"

Sam smiled, "It's my dick, Dean. What's the problem? It'd be like masturbating."

"Yeah, that may be so, but I'm not usually involved when you rub one out."

Sam winked, "See, that's where you're wrong. You've involved alright."

Dean's jaw dropped. What the hell was Sam trying to tell him? "I can't even look at you right now…not like that. Shit. This is just too fucking weird." He backed up. His back hit the wall and his towel started to slide down.

Sam shook his head, "Don't move, Dean. Just let me look at you."

"Are you narcissistic or something?"

Sam laughed, "Nah, just like knowing that the thought of being in my body and seeing me naked is getting you going."

"Why are you so okay with this?"

Sam shrugged, "I figure that since Cass did this that he has a reason for it. He wanted us to stop fighting, right? So, maybe if we stop fighting then he'll switch us back. What better way to show that we're not fighting then by making love?"

Dean's throat practically closed up. "You're joking."

Sam shook his head, "No, I'm not." He moved forward, pinning Dean up against the wall. "You know you want to wrap your lips around my cock, Dean."

Dean drew in a staggering breath. "No…I…that's…oh God, so good." Dean's guard was down and Sam had seized the opportunity to slip his own giant dick into Dean's mouth.

"Hmmm." Sam moaned. It was weirdly erotic for him. It was turning him on a lot more than it really should've. He palmed Dean's dick as he continued to slip his own down his throat.

Dean reached out and tried to grab handfuls of hair, but Sam no longer had much to grab onto. His hand wrapped around the back of the head that Sam was currently using to mouth-fuck Dean and he held on tightly.

Sam pulled back, "I don't want you coming yet, Dean. I want you bent over the bed first."

Dean's eyes slipped shut and his breathing was labored, "I can't even begin to tell you how wrong this is…"

Sam sighed, "Look, it really doesn't matter. You'd fight me on this if we were in our own skin. It would never be okay for you either way, so you might as well just suck it up and deal." Then he smirked, "literally." He got to his feet and put his hands on Dean's face and angled his face up to press their lips together.

Dean fought back at first, but eventually gave up. What was the point in fighting this? He wasn't kidding anyone by pretending that he didn't want it.

"Quit worrying so much, Dean." Sam whispered.

It was weird to hear his own voice whispered back to him. Very weird. But, he was just going to go with it. If this was what it would take to get Cass to put them back in their right bodies then that's what he'd do.

Sam moved Dean to his bed and pushed him down on it. "Is it weird that the sight of you…or me…like that is making me crazy?"

"The whole thing is weird." Dean breathed. But, he had to admit that looking up at a horny Sam, in his own body, was turning him on too. "But, I feel the same way."

Sam grinned. He slowly started to strip himself, giving Dean a really weird striptease. "You have no idea how gorgeous this body of yours is, Dean. You don't know how long I've wanted to touch it." He positioned himself right in front of a mirror, so he could watch himself touch that body he inhabited. His hands were all over Dean's body…pinching the nipples, squeezing the ass and slipping down the chiseled chest and abs to the perfectly shaped boner. Sam wrapped a hand around that boner and slowly began to stroke it, moaning.

Dean's mouth watered. "Fuck, that's hot."

"Yeah? You thinking about me touching your body? I love touching your body, Dean. You're gorgeous."

Dean moaned and felt Sam's huge erection begin to ooze precome. "You're dripping…"

Sam smiled, "Yeah, you're getting all hot, aren't you?"

Dean blushed, "Yeah…" It was the weirdest, hottest thing in the entire world. "Shit, it's heavy."

"Oh yeah. So heavy, so full…want you so fucking bad."

"Get over here." Dean husked out. "You're killing me here."

Sam moved to the bed and looked down at his own body, desperate and aching. His cock was so red. He'd never found himself sexy before, but with Dean inside it, he couldn't help but stare. "Touch yourself…my dick. Wrap that hand around it and make it feel good. I wanna watch."

Dean almost growled as he wrapped a hand around the base of that massive dick and began to stroke it. He was urgent, he needed friction and he needed it immediately.

"Hmmm….slower, Dean. This isn't a marathon. Wanna watch you come apart."

Dean's movements slowed considerably. He arched off the bed, panting and writhing. He was pretty sure he'd never been this horny before. It was different too because he was kind of experimenting with what would feel good in this different body. It didn't take him long to figure it out.

"I want to see you slip a finger in the hole, Dean."

Dean gasped. He slipped a finger into his mouth, sucking it greedily and then slid it down, under the balls and circled the hole. "You ever had anything in there?" He asked.

Sam smiled, "Maybe."

"Does maybe mean yes?"

"Might've fingered myself thinking about you a few hundred times…"

Dean moaned. He stilled his movements on the horse dick, not wanting to come before Sam was good and ready to fuck him. Instead, he pressed his first finger into that hole to the knuckle. He was nervous, but surprised about how easily it went in. He looked up at Sam's face and smiled.

Sam smiled back. He slipped two fingers into his mouth and slid them down to Dean's hole. "Hmm, gonna get your hole all stretched, Dean. I'd love to hope on and fuck myself with your tight hole."

"Oh God." Dean moaned.

"Then when I'm done, I'll switch."

"Don't care what you do…just want it…please."

Sam smiled. He loved to hear Dean begging. He slipped those two fingers inside and gasped at the intrusion. "God, you're fucking tight. You ever had anything in here?"

Dean shook his head, blushing.

"Nothing to be embarrassed about. I love that. I want to be your first…last…your everything."

They locked eyes. Dean was completely shocked. "You don't mean that…"

"Yes, I do." Sam moved forward, fingers still buried in that tight ass. He got on the bed and looked at his brother with dark eyes, "I am head over heels for you, big brother."

Dean looked up at Sam, eyes glassing up.

Sam gasped. He reached out to twirl his fingers in the long hair at the nape of his neck. "Is it okay if my dick takes your anal virginity?" He whispered.

Dean nodded, unable to meet Sam's probing gaze.

"Look at me."

Dean did.

They locked eyes and Sam bent down to kiss him softly, "It's okay. I won't do anything that will cause more than a dull soreness when you get your body back. I would never hurt you…or try and take something from you that you didn't want. I hope you know that."

Dean nodded.

"Shhh." Sam said. He could tell that Dean was fighting back tears. "Everything's okay. Just let me love you. Everything else will work itself out."

"Okay, Sammy."

Sam spit into Dean's hand and slipped it back to the opening and pressed it inside. He smiled at Dean, "Can I have my hand, please?"

Dean handed Sam his hand. Sam slipped two of those fingers into his mouth too and then he pulled it down to that tight opening and slipped them in beside the other two. He hissed, but really loved the burning.

"You promise this isn't going to hurt?" Dean whispered.

"No baby. Everything's fine. I just want to get stretched out so we can get this show on the road. I'm a little anxious."

Dean smiled. He was too.

* * *

Once Dean's hole was stretched, they both moved their fingers away. Sam looked down at Dean and smiled, "You want to use a condom?"

Dean shook his head, "No." He wanted to feel everything.

Sam nodded and moved forward, straddling his own body, Dean's ass cheeks parting so that the huge cock could rub between them erotically. They both gasped and started moving their hips together. Sam smiled as he gripped his erection and pressed it to Dean's opening.

Dean bit the lip he was wearing and closed his eyes, unable to watch his own body being impaled, whether he could feel it or not.

"Look at me." Sam whispered. He continued to lower Dean's body down onto that cock.

Hazel eyes opened and Dean gasped up at his own face. "Shit." He whined, "I had no idea my ass could feel so fucking good."

Sam smiled, "I knew." Once it was all the way in, Sam sat there for a minute, adjusting. He really didn't want Dean to hurt much when they switched back. He didn't want to do anything to scare him off doing this again in the future. He wanted to keep doing this forever.

Dean gripped at his own hips as Sam started moving. Dean groaned, Sam's voice sounding so foreign coming from him. "Want you Sam, want you…"

Sam bent down and captured his own lips in a passionate kiss. He picked up his pace, panting heavily against his mouth. "Not gonna last long, Dean." He whimpered.

Dean smiled and wrapped Sam's hand around his own dick. He started stroking it as he watched Sam, watched his own face reflecting the pleasure that Sam was feeling. It was hot, it was dirty and it was amazing.

They came together, each calling out the other's name.

Sam dropped Dean's body down on top of his own, letting his limp cock fall out. He gasped for breath against his neck. "I love you." He whispered.

Dean gasped, wrapping arms around his body and kissing over the freckles on his own cheeks. "I love you too, Sammy…so fucking much."

The room started to spin…or it felt like it did anyway. They clung to each other, watching as they switched back into their own bodies once again.

* * *

The first thing that Dean felt was the weird used feeling in his ass. It was really foreign.

Sam recovered quickly, his hands lovingly stroking through Dean's hair and down the back of his neck, "It's okay." He whispered. He didn't want Dean to start freaking out now that things were back to normal. He didn't want Dean to put his walls back up and go running.

Dean grunted. What the hell had just happened? He started to pull away, wanting to get off Sam's body and get cleaned up. He also really wanted to look into a mirror and make sure he looked like himself again.

Sam tightened his arms around Dean's body, "No, please. Just stay here with me." He peppered kisses over Dean's face, "Let me make love to you this time." He whispered.

Dean frowned, "It feels like you already did that."

Sam smiled, "You can have me again if you want…it'll be different this time."

Dean shook his head. He looked away, blushing, "No."

Sam frowned deeply, "Please Dean, please don't…"

Dean looked back at Sam, "No, Sammy, I just want to feel what it feels like to have you inside of me. It doesn't hurt, I'll be okay." Dean hadn't realized how much he really wanted that until that moment.

Sam smiled, tilting his head up to kiss Dean's pouty soft lips. "You sure?"

"Yeah. Just remember that I'm almost an anal virgin."

Sam laughed, "I promise I'll be extra gentle, Dean. I won't hurt you."

Dean smiled as he wrapped his arms tightly around his little brother and kissed him, his fingers twirling in Sam's long hair. He could really, really get used to this. It was a frightening experience, but it was also incredibly beautiful.

Sam flipped them over so that he was on top of Dean, smiling down at him. His breath caught in his chest at the beautiful man looking back at him. He had never seen Dean quite like this before. He vowed to himself that he was going to make Dean happy if it was the last fucking thing he ever did.


End file.
